Chall



Witness A. L. PASCHALL.

GRINDING MILL.

APPLlcATsoN FILED Au .15.191s.

Patented July 15, 19M.

2 SHEETS-SHEET l.

A. L. PASCHALL.

GRINDING MILL.

APPLICATION FILED AuG.15, 191e.

l y3 l @,@3 l. Patented July 15, 1919.

2 SHEETS-SHEET 2.

AIRWAJTD LYNNE PASCHALL, 0F SPRINGFIELD, OHIO, ASSIGNOR T0 THE BAUER BROS. COMPANY, 0F SPRINGFIELD, OHIO, A CORPORATION 0F OHIO.

GRINDING-MILL.

Specification of Letters Patent.

Patented July 15, 1919.

Application filed August 15, 1916. Serial No. 114,967.

having longitudinally arranged driving shafts.

One of the objects of the invention is to provide improvements in the arrangement for causing theV separation of the grinding disks under certain conditions such as the entrance of foreign substances between the same.

A further object of the invent-ion is to provide means for relieving and utilizing the air pressure in the grinding casing, due

to the revolving action of the grinding disks,

to secure a more effective feed of the material to be ground.

In the accompanying drawings Figure 1 is a longitudinal section of a machine embodying my improvements.

Fig. 2 is a transverse section of a of the same.

Fig. 3 is a section on the line 3-3 of Fig. 2.

Fig. 4 is a top plan of a portion of the same.

Fig. 5 is a. detail section.

portion In mills of this character it has been common to make provision for the separation of the grinding disks to obviate the danger of breakage by the entrance into the mill of hard foreign substances, this separation being accomplished by a longitudinal movement of one of the driving shafts and its disk. In certain types of mills it was usual to provide positive means for throwing the movable shaft and its disk into the proper grinding position and to rely upon a spring for moving the shaft and disk in the opposite direction. It was also usual in that type of mill to provide other springs for yieldingly holding the movable disk in grinding relation with the stationary disk so that the disks could automatically separate under certain conditions; the tension of these latter springs being of course in the opposite direction and against the tension of the first mentioned spring. This has resulted in making it necessary to have the first mentioned springof a comparatively light character so that it could not at all times be relied upon to quickly separate the disks, as it was found that the driving action of 'the belt upon the pulley of the movable shaft would tend to counteract the tension of this spring and prevent its quick and effective action. In order to overcome this diliiculty I have provided means for shifting the movable shaft and its disk positively and in either direction when it is desired to accomplish this by what is called the quick release devices, but at the same time provide for yieldingly holding the shaft and disk in proper driving relation-by springs which will permit their automatic separation.

The grinding disks are of the usual form, represented by 1 and 2. The grinding disk 1 is connected with the shaft 3, which is mounted in suitable bearings on the base 4- and this shaft and its grinding disk are immovable longitudinally. The other disk 2 i's connected with the shaft 5, the inner end of which is supported in the bearings 6 of the bearing block7 and the outer end oflwhieh is supported in bearings in the box 8. The bearings employed in the different boXes are of the ball type, it being necessary to describe only those in the boX 8 in order to -illustrate the improvementsv which I have made. The shaft 5 is reduced at its extreme outer end and between the shoulder formed by the reduction and the nut 9 is a race 10.

Fitted in the box 8 is the co-acting race l1.

ball bearing 11n being placed between the two races in the usual way. Slidably mounted in the boX 8 is a head or blo/.lk 1Q to which is swivelly connected a screw 13 which projects loosely through the end of the bearing box and is threaded in a crossbar 14, slidably mounted on the stationary pins 15 which project from the end of the box; a'jam nut 14: being employed to keep the screw from turning in the bar after the proper adjustments have been made.y Pivotally connected to each end of the cross-bar 14 is a link 16, the opposite ends of the links being in turn pivotally connected to projecting arms 17 of a bifurcated lever 18, the respect-ive parts of which are pivotally connected with sleeves 19 slidably arranged on rods 20 which are clamped to laterally eX- tending lugs or ears 21 projecting from the sides of the bearing box 8 and project rear; wardly therefrom. Between the sleeves 19 and collars 22, held in position by nuts 22', are interposed coil springs 23. It is these springs 23 which hold the grinding disks in grinding relation with each other. 4When the parts are in the position shown in Fig. 4, it will be seen that the links 16 and arms 17 are in longitudinal alinement with each other so that the springs will tend to hold the cross-bar 14: toward the center of the machine, the movement being limited, however, by the contact of the sliding sleeves 19 with the ears 21 or interposed collars 24.-. When the disk 2 is caused to separate from the disk 1 andjits shaft 5 forced longitudinally, it is against the tension of these springs 23, and if desired a quick release may be accomplished by throwing the bifurcated lever away from the center of the machine so as to cause the arms 17 to push the links 16 and hence the cross-bar 14:, screw 13 and block 12 away from the center of the machine.

As before mentioned, it was the former practice to employ a spring to assist in the separation of the disks, and formerly this spring was inserted between the inner end of the bearing box 8 and the ring 25. In the present construction, however in which this spring is dispensed with, ll have provided gibs 26 arranged in slots 27 in thewalls of the box 8 and embracing the head A22 and ring 25 so as to connect them together, as a result of which, when the head 12 is pulled by the operation previously described, the bearings, ring 25, shaft 5 and disk 2 will all move positively together. Two of these gibs are preferably employed.y arranged diametrically opposite each other and when the parts are removed from the box 8 the gibs are readily removable so as to permit the separation of the parts of 'the bearing.

Inorder to prevent the head 12 and ring 25 from turning, I provide the head 12 with small projecting ribs 12t and provide the i ring 25 with similar ribs 25, which ribs fit in recesses formed in the `respective ends of each of the gibs 26 and thus lock'the head and ring to the gibs' so far as rotary movement is concerned.

1n the operating of grinding, a pressure passageway of air will accumulate in the casing 28 due to the revolving action of the grinding disks and this pressure of air will materially interfere with the proper feed of the material from the spout 29, which material, it will be understood, finds its way through Lthe openings 30 about the hub of the disk 1. In order to overcome this difficulty and toutilize the air pressure to assist in the feeding operation, I have provided an opening or 31 leading from the upper part of the casing 28 to a point in the hopper 29 above the point of discharge therefrom.

` The result of this arrangement is that the air, instead of accumulating and forming a pressure in the casing 28 .will circulate through the same and into the spout 29 through the passageway 31 and thence back into the casing through the openings 30, thereby materially assisting in the feed of the material. The wall of the spout overlies the opening 31, as indicated at 29a, so as t0 tend to deflect the air downwardly.

Having thus described my invention, I claim:-

1. 1n an attrition mill, a casing, a revoluble grinding member in said casing, a chute to receive the material to be ground and discharge the same by gravity near the axis of said grinding member and a passage way from said casing having opposite vertical walls providing a downward discharge into said chute whereby thel material to be ground will fall free of the discharge opening of said passageway and beassisted in its fall by the pressure from said opening.

2. In an attrition mill, a casing, revoluble grinding members in said casing, a` chute to receive the material to be ground and dis'- charge the same by gravity near the aXis ofl said grinding members and a passage way from said casing having a downward discharge into said chute through a` vertically disposed opening in a set off in the wall of said chute whereby the material to be ground Will fall free of the discharge opening of said passage way and be assisted in its fall by the pressure from said opening. In v testimony whereof, I have hereunto set my hand this 11th day of ugust,19i(. 

